At the beginning of your upkeep, put a pain counter on Torture Chamber.
At the beginning of your end step, Torture Chamber deals damage to you equal to the number of pain counters on it.
![1](/Handlers/Image.ashx?size=small&name=1&type=symbol)
,
![Tap](/Handlers/Image.ashx?size=small&name=tap&type=symbol)
, Remove all pain counters from Torture Chamber: It deals damage to target creature equal to the number of pain counters removed this way.